Seat structure member and manufacturing method of same

ABSTRACT

A seat structure member includes a cover and a seat pad. The cover and the seat pad are integrated when the seat pad is foam molded. A recessed portion is formed on a portion of a surface of the seat pad that is covered by the cover. Integrated molding of the seat pad and the cover is avoided at a location of the recessed portion, and a space of the recessed portion is formed between the seat pad and the cover.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2013-037172 filed onFeb. 27, 2013 including the specification, drawings and abstract isincorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a seat structure member and a manufacturingmethod thereof. More particularly, the invention relates to a seatstructure member in which a cover and a seat pad of a seat for a vehiclesuch as an automobile are integrated when the seat pad is foam molded,as well as a manufacturing method of this seat structure member.

2. Description of Related Art

A vehicle seat includes a seat cushion and a seat pad as maincomponents. A seat structure member that forms this seat cushion or aseat back is formed by covering a seat pad of foam urethane or the likewith a cover. This type of seat structure member is typically used in afoam molded seat with an integrated cover (hereinafter also referred toas a “cover integrated foam molded seat”), in which the cover isintegrally molded when the seat pad is foam molded, because of theconvenience of handling and the like at the time of assembly. Therefore,the cover is integrated with the seat pad so that it can be handled as asingle part, thus facilitating handling, as well as to improve theappearance (see Japanese Patent Application Publication No. 2005-192635(JP 2005-192635 A) below). Meanwhile, a seat slide mechanism and aheight adjustment mechanism are arranged on a lower portion of a seatcushion, and a reclining mechanism for tilting a seat back is arrangedon a connecting portion of the seat cushion and the seat back. To coverthese mechanisms and improve the appearance of the overall seat, ashield that serves as a design cover is arranged around the lower sideof the seat cushion. This shield is arranged extending from a frontsurface side of the seat cushion to a side surface side of the seatcushion. As a result, various seat equipment is covered by the shieldarranged on the lower portion, together with the seat structure memberof the cover integrated foam molded seat described above that isarranged on the upper portion of the seat cushion, thereby improving theappearance of the overall seat.

SUMMARY OF THE INVENTION

In the arrangement configuration of the shield and the seat structuremember of the cover integrated foam molded seat described above, fromthe viewpoint of appearance, an end edge of an upper edge of the shieldis arranged contacting the cover without a gap in between. The shield isarranged fixed in the vertical direction to a base portion of the seatcushion, but the seat structure member of the cover is arranged so as tobe able to move in the vertical direction by the height adjustmentmechanism. Therefore, the end edge of the shield and the cover arearranged in relative sliding contact with one another. With thisrelative sliding contact, the cover is rubbed on in a strong frictionalcontact state from the spring force of the seat pad because it (i.e.,the cover) is integrated by the foam molding of the seat pad. Therefore,the cover may become damaged, which may adversely affect the appearance,and an abnormal noise may be produced.

The invention thus provides a cover integrated foam molded seat in whichthe cover is able to easily bend (flex), by providing a recessed space(i.e., a space formed by a recessed portion) between the seat pad andthe cover at a location where another member contacts the cover, as wellas a manufacturing method of this cover integrated foam molded seat.

A first aspect of the invention relates to a seat structure member thatincludes a cover and a seat pad. The cover and the seat pad areintegrated when the seat pad is foam molded. A recessed portion isformed on a portion of a surface of the seat pad that is covered by thecover. Integrated molding of the seat pad and the cover is avoided at alocation of the recessed portion, and a space of the recessed portion isformed between the seat pad and the cover.

According to this aspect, a recessed portion having a space whereintegrated molding is avoided is provided between the seat pad and thecover, on a portion of the surface of the seat pad. Therefore, even ifanother member contacts the cover at a location where the space isprovided by the recessed portion, the cover is able to easily bend, sothe cover will not be damaged by friction (i.e., rubbing) or the like.As a result, the appearance of the cover is able to be well maintainedfor a long time.

In the aspect described above, a position of the recessed portion formedon the surface of the seat pad may be a location other than a contactsurface that is contacted by an occupant when the occupant is seated.With this structure, the seating comfort of the seat as felt by theseated occupant will not be affected much.

In the aspect described above, a position of the recessed portion formedon the surface of the seat pad may be a position corresponding to aposition of an end edge of a shield arranged on an outside surface of aseat. Also, in the aspect described above, the seat pad may be used in aseat cushion, and the recessed portion may be formed on a joiningportion of the seat cushion, which joins with a seat back at a rearportion of the seat cushion. With this structure, good design of theoverall seat is able to be maintained for a long time.

Also in the aspect described above, the seat structure member may alsoinclude a film through which foam material is unable to pass, andintegrated molding of the seat pad and the cover may be avoided byarranging the film between the seat pad and the cover.

Furthermore, a second aspect of the invention relates to a manufacturingmethod of a seat structure member. This manufacturing method includesforming a protrusion that protrudes inward on an inside surface of aportion that forms a foaming chamber for a seat pad, on one die andanother die that form the foaming chamber; applying, to a cover, meansthat will not be integrated with the seat pad when the seat pad is foammolded, at a location on the cover that corresponds to a location of theprotrusion when placing the cover on the inside surface of the foamingchamber; arranging the cover following a shape of the protrusion andfoam molding the seat pad; and forming a space of a recessed portionbetween the seat pad and the cover, by releasing the one die and theother die after foam molding the seat pad. This manufacturing methodmakes it possible to manufacture a seat structure member in which aspace of a recessed portion is formed between the cover and the surfaceof the seat pad, by forming a protrusion that protrudes inward on aportion of the inside surface of a forming die that forms a foamingchamber, applying means that will not be integrated with the seat padwhen the seat pad is foam molded, to the cover at a locationcorresponding to the location of this protrusion, and foam molding theseat pad.

As described in the first and second aspects of the invention, in acover integrated foam molded seat, the cover is able to easily bend byproviding a space of a recessed portion between the seat pad and thecover at a location where another member contacts the cover, and is thusable to be kept in a good state for a long time even if another membercontacts the cover at that location.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, advantages, and technical and industrial significance ofexemplary embodiments of the invention will be described below withreference to the accompanying drawings, in which like numerals denotelike elements, and wherein:

FIG. 1 is a sectional view of a front portion of a seat cushionillustrating one example embodiment of a seat structure member of theinvention;

FIG. 2 is a sectional view showing a frame format of a state in whichthe seat structure member is integrally foam molded by a forming diethat includes an upper die and a lower die;

FIG. 3 is a sectional view of a frame format showing a state in whichthe seat structure member is released after being integrally foam moldedby the forming die that includes the upper die and the lower die;

FIG. 4 is a sectional view of a modified example of the exampleembodiment shown in FIG. 1; and

FIG. 5 is a view showing a frame format of a modified example in which arecessed portion is provided in a different position.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, an example embodiment for carrying out the invention willbe described with reference to the accompanying drawings. This exampleembodiment illustrates a case of a seat structure member 14 of a seatcushion 10 of a vehicle seat.

The vehicle seat normally includes the seat cushion 10 and a seat back.FIG. 1 is a sectional view of a front portion of the seat cushion 10.The seat structure member 14 on an upper portion of the seat cushion 10is formed by a seat cover 16 and a seat pad 24 that are integrallymolded by integrated foam molding. The seat cover 16 has a three-layerstructure. The three layers, i.e., a cover 18, a soft laminate middlemember 20, and a low air permeable laminate back surface member 22, arelaminated together in this order from a surface side so as to beintegrally formed in advance. The three layered seat cover 16 thatincludes this cover 18 is integrally molded with the seat pad 24 whenthe seat pad 24 is foam molded. The cover 18 has a good appearance as ittends not to wrinkle and the like even when used, due to it beingintegrally foam molded with the seat pad 24. In addition, the cover 18is easy to handle when assembling the seat. A height adjustmentmechanism, not shown, is provided on a lower portion of the seat cushion10, so the height of the front portion of the seat cushion 10 is able tobe adjusted according to a seated person (also referred to as a “seatedoccupant”). Also, a seat slide mechanism, also not shown, is alsoarranged on a lower portion of the seat cushion 10, so the position ofthe entire seat in the front-back direction is also able to be adjustedaccording to the seated person. A shield 26 is arranged in a positionbelow a front surface portion and a side surface portion of the seatcushion 10 to cover and hide these mechanisms. A front shield 26A thatis arranged in a position below the front surface portion of the seatcushion 10 is shown in FIG. 1. As a result, the mechanisms arranged onthe lower portion of the seat cushion 10 are unable to be seen from theoutside, so the appearance of the entire seat is good. The front shield26A is attached to a base portion of the seat that does not move in thevertical direction, so the seat cushion 10 is displaced relative to thefront shield 26A when the seat cushion 10 is adjusted and moved in theheight direction.

As shown in FIG. 1, an end edge 26 x of an upper end the front shield26A is arranged contacting the cover 18 of the seat cover 16 with no gaptherebetween in order to improve the appearance. Therefore, there issliding contact between the end edge 26 x of the front shield 26A andthe cover 18 of the seat cover 16 at this area following the relativedisplacement of the seat cushion 10 and the front shield 26A. A recessedportion 30 in which the shape of the surface of the seat pad 24 isrecessed inward is formed in a position of the seat pad 24 thatcorresponds to the position of the cover 18 where the end edge 26 x ofthe upper end of this front shield 26A contacts the cover 18. A portionof the seat cover 16 that corresponds to the location where the recessedportion 30 is formed is configured such that the low air permeablelaminate back surface member 22 and the soft laminate middle member 20are not integrated but are instead able to separate. Therefore, when theseat pad 24 is foam molded, the back surface member 22 and the seat pad24 become a single integrated unit, a space 28 of the recessed portion30 is formed between the back surface member 22 and the middle member20. The cover 18 and the soft laminate middle member 20 are integrallyformed in advance, and are arranged following the shape of the surfaceof the seat pad 24, except for the recessed portion 30, by the tensionthereof. More specifically, in this example embodiment, the middlemember 20 and the back surface member 22 of the seat cover 16 that arearranged in a position lower than the position where the recessedportion 30 is formed, when viewed in FIG. 1, are separated until theirterminal ends (i.e., the terminal ends of these members 20 and 22).Also, the back surface member 22 is integrated with the seat pad 24 byfoam molding the seat pad 24, so the middle member 20 and the cover 18that are integrally formed in advance are fixed by being attached in astate in which tension is applied to a retaining portion 34A of a seatframe 34 by a retaining clip 32 that is attached to the end portion. Asa result, the space 28 is formed at the location of the recessed portion30 of the seat pad 24, between the cover 18 and the seat pad 24. Thisspace 28 is specifically formed between the back surface member 22 andthe middle member 20 of the seat cover 16 at the position of therecessed portion 30 of the seat pad 24. The foam material of the seatpad 24 will not pass through the back surface member 22 and penetrate tothe position of the middle member 20 during the foam molding when theseat cover 16 is integrated with the seat pad 24 when the seat pad 24 isfoam molded, because the back surface member 22 of the seat cover 16 isformed by a low air permeable laminate.

As described above, when the space 28 resulting from the recessedportion 30 of the seat pad 24 is formed in a location on the back sideof the cover 18 where the end edge 26 x of the upper end of the frontshield 26A slidingly contacts the cover 18, the cover 18 and the softlaminate middle member 20 are able to bend easily. Therefore, even ifthe cover 18 slidingly contacts, and is thus rubbed on by, the end edge26 x of the upper end of the front shield 26A due to the height of thefront portion of the seat cushion 10 being adjusted, the cover 18 isstill able to easily bend, so damage to the cover 18 from this friction(i.e., rubbing) is able to be inhibited. Also, in the example embodimentdescribed above, the position where the recessed portion 30 is formed onthe seat pad 24 is a position on the front surface side of the seatcushion 10. This position is a location other than a contact surfacethat the seated occupant contacts when seated, so the seating comfort ofthe seat as felt by the seated person will not be affected much.

Next, a manufacturing method of the seat structure member 14 that formsthe seat cushion 10 described above will be described. FIG. 2 is a viewshowing a frame format of a state in which the seat structure member 14is integrally foam molded by a forming die 36. FIG. 3 is a sectionalview of a frame format showing a state in which the seat structuremember 14 is released after being integrally foam molded. The formingdie 36 includes a lower die 38 and an upper die 40, and has a foamingchamber (a cavity) 42 formed inside, as shown in FIG. 2. The shape ofthe space of the foaming chamber 42 corresponds to the shape of the seatpad 24 after forming. More specifically, the shape of the space of thefoaming chamber 42 is a shape that superficially covers the seat cover16. The shape of the foaming chamber 42 in FIG. 2 is such that thevertical position of the seat structure member 14 of the seat cushion 10shown in FIG. 1 is inverted. That is, the positional relationship is onein which the lower surface side of the lower die 38 will become theupper surface side of the seat cushion 10. The forming die 36 is formedwith a protrusion 44 corresponding to the shape of the recessed portion30 of the seat pad 24, formed in a position corresponding to therecessed portion 30, in the foaming chamber 42 of the upper die 40. Oneof the lower die 38 and the upper die 40 in this example embodiment isan example of one die of the invention, and the other is an example ofthe other die of the invention. This forming die 36 (i.e., both thelower die 38 and the upper die 40) is made of aluminum.

The seat cover 16 is formed in advance. The basic structure of the seatcover 16 is one in which the cover 18, the soft laminate middle member20, and the low air permeable laminate back surface member 22 areintegrally laminated together in order from the surface layer side.However, the middle member 20 and the back surface member 22 of the seatcover 16 that are arranged at the position of the protrusion 44 of theupper die 40 are not integrated together, but are instead able toseparate. In this example embodiment, the middle member 20 and the backsurface member 22 at a portion of the seat cover 16 arranged in aposition higher than the position of the protrusion 44 shown in FIG. 2are not integrated together, but are instead able to separate. Whenintegrally foam molding the seat pad 24 and the seat cover 16 includingthe cover 18, first the seat cover 16 is placed on the inside surface ofthe foaming chamber 42 that is formed by matching (i.e., joining) thelower die 38 with the upper die 40. At this time, the seat cover 16 isplaced such that a portion where the back surface member 22 and themiddle member 20 are not integrated together but are instead able toseparate is positioned at the position of the protrusion 44 of the upperdie 40. Then a foaming liquid is poured into the foaming chamber 42 intowhich the seat cover 16 has been placed. In order to perform thisoperation, more specifically, the upper die 40 is formed divided into afirst upper die 40 at a location of the portion where the seat cover 16is placed, and a second upper die 40 at a location of the other portion.FIG. 2, however, is a view showing a frame format and is thus simplifiedso this is not shown. The seat cover 16 is placed on the inside surfacein the foaming chamber 42 from the location where the second upper die40 that is not yet matched is to be arranged, while the first upper die40 is matched with the lower die 38, and the foaming liquid is pouredin. Then, the second upper die 40 is matched, thereby closing andforming the foaming chamber 42. The lower die 38, the first upper die40, and the second upper die 40 that together form the forming die 36are pivotally connected together by a hinge mechanism. Therefore, first,the first upper die 40 is able to be matched to the lower die 38 bybeing pivoted, and in this state, the seat cover 16 is placed in. Thenthe foaming liquid is poured in. Next, the second upper die 40 ispivoted so as to be matched up, thereby closing the foaming chamber 42so foam molding can be performed.

In this state, the forming die 36 is heated and foam molding isperformed. When the seat pad 24 is formed by this foam molding, foammaterial of the seat pad 24 penetrates the back surface member 22 of theseat cover 16, so as to be integrated with the seat cover 16 thatincludes the cover 18, as shown in FIG. 3. Then, the recessed portion 30corresponding to the protrusion 44 of the upper die 40 shown in FIG. 2is formed on the surface of the formed seat pad 24, as shown in FIG. 3.FIG. 3 is a view showing a state in which the upper die 40 is released(i.e., separated) from the lower die 38. As is evident from the drawing,at the location of the recessed portion 30, the back surface member 22of the seat cover 16 is integrated following the shape of the recessedportion 30 of the seat pad 24, and the cover 18 and the middle member 20of the seat cover 16 are in a state recessed inward along the protrusion44 of the upper die 40 during foam molding shown in FIG. 2, but are thenpulled on by tension following the shape of the surface of the seat pad24 except for the shape of the recessed portion 30, as shown in FIG. 3.As a result, the space 28 is formed between the middle member 20 and theback surface member 22 at the location of the recessed portion 30. Thatis, the space 28 resulting from the recessed portion 30 of the seat pad24 is formed between the seat pad 24 and the cover 18 of the invention.As described above as well, the foam material that penetrates the seatcover 16 during foam molding will not penetrate to the position of themiddle member 20 because the back surface member 22 is formed by a lowair permeable laminate, so the formation of the space 28 between theback surface member 22 and the middle member 20 at the position of therecessed portion 30 will not be effected. Accordingly, the space 28 isable to be reliably formed on the back side of the cover 18, at theposition of the middle member 20, thus facilitating bending deformationof the cover 18. As a result, the cover 18 is able to bend easily evenif the end edge 26 x of the front shield 26A moves while contacting thecover 18. Therefore, damage is able to be minimized, so a goodappearance is able to be maintained for a long time.

FIG. 3 is a view of a modified example of the forming method of thespace 28 formed in the recessed portion 30 of the seat pad 24. In theexample embodiment described above, means by which the cover 18 of theinvention will not be integrated with the seat pad 24 when the seat pad24 is foam molded is configured such that the back surface member 22 andthe middle member 20 of the seat cover 16 are not integrated, but areinstead able to separate. In the modified example shown in FIG. 4, afilm 46 through which the foam material is unable to pass is adhered atthe location of the back surface member 22 of the seat cover 16 thatcorresponds to the location of the recessed portion 30 of the seat pad24. As a result, when the upper die 40 is released after the recessedportion 30 has been formed by the protrusion 44 of the upper die 40 whenthe seat pad 24 is foam molded, the entire seat cover 16 to which thefilm 46 is adhered separates from the surface of the recessed portion 30due to the tension, and follows the shape of the surface of the seat pad24, except for the recessed portion 30, thus enabling the space 28 to beformed in the recessed portion 30. In this modified example, whenplacing the seat cover 16 in the foaming chamber 42, the seat cover 16is able to be placed while visually recognizing the position where thisfilm 46 is adhered, so the film 46 is able to be reliably placed ontothe upper die 40.

FIG. 5 is a view of a modified example of the position of the recessedportion 30 formed on a seat structure member of the seat cushion 10. Inthe modified example shown in FIG. 5, the recessed portion 30 is formedat a joining portion of the seat cushion 10, which joins with a seatback 12 at a rear portion of the seat cushion 10. The seat back 12 tiltsforward and backward by a reclining mechanism, so the seat back 12 moveswhile a lower portion of thereof is in slidingly contact with thesurface of the seat cushion 10. By forming the recessed portion 30 atthis location and making the cover 18 easier to bend, damage to thecover is able to be suppressed so a good appearance is able to bemaintained for a long time, just as described above.

While example embodiments of the invention have been described, theinvention may also be carried out by other modes aside from the exampleembodiment described above. For example, the shape of the recessedportion formed on the surface of the seat back is an angular shape inthe example embodiment described above. Alternatively, a space that isround or the like may also be formed. In this case, the shape ispreferably one that facilitates release at the time of mold release. Inparticular, with a forming die that is matched by pivoting, as theforming die described above is, the shape is preferably a recessed shapethat takes the pivot direction into account. Also, in the exampleembodiment described above, the recessed portion is formed on the seatcushion, but in the invention, the recessed portion may also be formedon a seat back or a headrest or the like.

What is claimed is:
 1. A seat comprising: a cover; and a foam moldedseat pad, wherein the cover and the foam molded seat pad are integratedsuch that a foam material that defines the foam molded seat padpenetrates a back surface member of the cover, a recessed portion isdefined on a front surface side of the foam molded seat pad and iscovered by the cover, integration of the foam molded seat pad and thecover is avoided at a location of the recessed portion, and a space ofthe recessed portion is defined between the foam molded seat pad and thecover.
 2. The seat according to claim 1, wherein the foam molded seatpad defines a seat cushion; and the recessed portion is provided on ajoining portion of the seat cushion, the joining portion is joined witha seat back at a rear portion of the seat cushion.
 3. The seat accordingto claim 1, further comprising: a film through which foam material isunable to pass, the film being arranged between the foam molded seat padand the cover, wherein integration of the foam molded seat pad and thecover is avoided by the film being arranged between the foam molded seatpad and the cover.
 4. A seat comprising: a cover; a foam molded seatpad; and a shield having an end edge and arranged on an outside surfaceof the seat, wherein the cover and the foam molded seat pad areintegrated, a recessed portion is defined on a front surface side of thefoam molded seat pad and is covered by the cover, integration of thefoam molded seat pad and the cover is avoided at a location of therecessed portion, a space of the recessed portion is defined between thefoam molded seat pad and the cover, a position of the recessed portioncorresponds to a position of the end edge of the shield, and the spaceof the recessed portion is interposed between the foam molded seat padand the end edge of the shield.
 5. A seat comprising: a cover; a foammolded seat pad; a recessed portion defined on a portion of a surface ofthe foam molded seat pad and covered by the cover; and a shield havingan end edge and arranged on an outside surface of the seat, wherein thecover and the foam molded seat pad are integrated, integration of thefoam molded seat pad and the cover is avoided at a location of therecessed portion, a position of the recessed portion corresponds to aposition of the end edge of the shield, and a space of the recessedportion is defined between the foam molded seat pad and the cover, thespace being interposed between the foam molded seat pad and the end edgeof the shield.
 6. The seat according to claim 5, wherein the cover andthe foam molded seat pad are integrated such that a foam material thatdefines the foam molded seat pad penetrates a back surface member of theseat cover.